U.S. patent number 10,675,902 [Application Number 15/246,873] was granted by the patent office on 2020-06-09 for insulator film formation method by flexographic printing and flexographic printing plate.
This patent grant is currently assigned to JAPAN AVIATION ELECTRONICS INDUSTRY, LIMITED. The grantee listed for this patent is JAPAN AVIATION ELECTRONICS INDUSTRY, LIMITED. Invention is credited to Naoki Iwao, Yutaro Kogawa, Mitsutoshi Naito, Akitoshi Sakaue, Mitsunori Sato, Yutaka Takezawa.
United States Patent |
10,675,902 |
Sakaue , et al. |
June 9, 2020 |
Insulator film formation method by flexographic printing and
flexographic printing plate
Abstract
A method of forming an insulator film by flexographic printing
is provided with which an insulator film is formed on a printing
object by using ink as an insulator film material and a
flexographic printing plate with halftone dots convexly formed on a
convex portion thereof that defines a printing pattern. A halftone
dot condition change region with a condition of the halftone dots
varied such that an ink retention volume therein is smaller than
that in other region on the convex portion is provided on a part of
the convex portion corresponding to an edge of the printing
pattern.
Inventors: |
Sakaue; Akitoshi (Tokyo,
JP), Iwao; Naoki (Tokyo, JP), Sato;
Mitsunori (Tokyo, JP), Takezawa; Yutaka (Tokyo,
JP), Kogawa; Yutaro (Tokyo, JP), Naito;
Mitsutoshi (Tokyo, JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
JAPAN AVIATION ELECTRONICS INDUSTRY, LIMITED |
Tokyo |
N/A |
JP |
|
|
Assignee: |
JAPAN AVIATION ELECTRONICS
INDUSTRY, LIMITED (Tokyo, JP)
|
Family
ID: |
58561746 |
Appl.
No.: |
15/246,873 |
Filed: |
August 25, 2016 |
Prior Publication Data
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|
|
Document
Identifier |
Publication Date |
|
US 20170113453 A1 |
Apr 27, 2017 |
|
Foreign Application Priority Data
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|
|
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Oct 21, 2015 [JP] |
|
|
2015-206850 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B41M
3/006 (20130101); G06F 3/0446 (20190501); B41M
1/04 (20130101); G06F 3/0445 (20190501); B41F
5/24 (20130101); B41N 1/00 (20130101); B41M
3/00 (20130101); B41N 1/16 (20130101); B41P
2200/12 (20130101); B41F 19/001 (20130101); G02F
1/1337 (20130101); B41N 1/22 (20130101); B41P
2217/50 (20130101); G06F 3/044 (20130101); B41N
1/12 (20130101); G02F 1/1303 (20130101); G06F
2203/04103 (20130101); B41M 1/26 (20130101); G02F
1/13378 (20130101) |
Current International
Class: |
B41M
3/00 (20060101); B41N 1/16 (20060101); B41F
5/24 (20060101); B41M 1/04 (20060101); B41N
1/00 (20060101); B41M 1/26 (20060101); B41N
1/22 (20060101); G02F 1/1337 (20060101); G06F
3/044 (20060101); B41N 1/12 (20060101); G02F
1/13 (20060101); B41F 19/00 (20060101) |
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|
Primary Examiner: Vonch; Jeffrey A
Attorney, Agent or Firm: Greenblum & Bernstein,
P.L.C.
Claims
What is claimed is:
1. A flexographic printing plate for receiving ink from an anilox
roll and transferring ink to a printing object, the flexographic
printing plate comprising: a convex portion having a top surface
with convexly formed halftone dots thereon defining a printing
pattern, the halftone dots having top surfaces to retain the ink
thereon defining an ink retention volume, and the halftone dots
being arranged such that a number of lines per inch of the printing
pattern increases toward an inner and/or outer peripheral edge of
the printing pattern such that the ink retention volume decreases
toward the inner and/or outer peripheral edge of the printing
pattern.
2. The flexographic printing plate according to claim 1, wherein
the halftone dots are arranged to keep a halftone dot area ratio
constant.
3. The flexographic printing plate according to claim 2, wherein
the number of lines per inch is set to 300 LPI and increases toward
the inner and/or outer peripheral edge to 600 LPI, wherein the
halftone dot area ratio is 70%.
4. The flexographic printing plate according to claim 1, the number
of lines per inch of the printing pattern increases in a step-wise
fashion.
5. The flexographic printing plate according to claim 1, wherein
the number of lines per inch of the printing pattern increases at
only a portion of the inner peripheral edge and/or outer peripheral
edge.
6. The flexographic printing plate according to claim 1, wherein
the number of lines per inch of the printing pattern increases
around the entirety of the inner peripheral edge and/or outer
peripheral edge in the shape of a loop.
7. The flexographic printing plate according to claim 6, wherein
the number of lines per inch increases concentrically in a
step-wise fashion.
8. The flexographic printing plate according to claim 6, wherein
the inner peripheral edge is a rectangular shape having four sides,
wherein the number of lines adjacent each side may be the same or
different.
9. The flexographic printing plate according to claim 8, wherein
the four sides comprises a first side and an opposing second side
and a third side and an opposing fourth side, wherein adjacent the
first side is a first number of lines per inch, adjacent the second
number of lines per inch, and adjacent a third and fourth sides is
a third number of lines per inch, wherein the first number of lines
per inch is greater than the second number of lines per inch and
the second number of lines per inch is greater than the third
number of lines per inch.
10. A method of forming an insulator film by flexographic printing,
the method comprising: forming an insulator film on a printing
object using ink of an insulator film material and the flexographic
printing plate of claim 1.
11. The method of forming an insulator film by flexographic
printing according to claim 10, wherein the number of lines per
inch of the printing pattern increases at only a portion of the
outer peripheral edge, the portion being at a rear end side in a
printing direction of the printing pattern.
12. The method of forming an insulator film by flexographic
printing according to claim 10, wherein the insulator film is
formed between two conductor films and has a through hole for
connecting the two conductor films, and the through hole
corresponds to an inner peripheral edge in the printing pattern in
the printing pattern the number of lines per inch of the printing
pattern increases around the entirety of the inner peripheral edge
in the shape of a loop.
Description
TECHNICAL FIELD
The present invention relates to a method of forming an insulator
film by flexographic printing and a flexographic printing plate
used in the method.
BACKGROUND ART
If not vacuum processing such as sputtering but a printing process
can be used in a process of forming a film such as an insulator
film or a conductor film, not only improvement in productivity but
also cost reduction due to unnecessity of an expensive film forming
apparatus will be expected.
Japanese Patent Application Laid Open No. 2001-51259 (hereinafter
referred to as "Patent Literature 1") discloses that, in a
substrate used for a liquid crystal device, a surface protection
film which is an insulator film covering an electrode pattern
formed as a conductor film on the substrate is formed by
flexographic printing. FIGS. 1A, 1B, 2A, and 2B illustrate an
insulator film formed by flexographic printing as disclosed in
Patent Literature 1. In FIGS. 1A, 1B, 2A, and 2B, reference numeral
11 represents the substrate, reference numeral 12 represents the
electrode pattern (conductor film), and reference numerals 13, 13a,
and 13b represent a coating film, a lower coating film, and an
upper coating film, respectively, each of which is formed with a
liquid precursor for forming an insulator film transcribed and
applied on the electrode pattern 12.
Patent Literature 1 describes the following technical matters with
reference to FIGS. 1A, 1B, 2A, and 2B.
(1) When a liquid precursor is applied by flexographic printing, as
illustrated in FIG. 1A, a part in the vicinity of an edge 14 of the
coating film 13 is protruded such that the film thickness thereof
is approximately twice the film thickness of the inner region of
the film, and when the thickness of this protrusion 15 approaches
around 1500 .ANG., cracking occurs on the occasion of cleaning and
rubbing treatment. Such cracking causes the coating film 13 to be
peeled off. In FIG. 1A, the thickness limit of the surface
protection film that can be formed is 750 .ANG..
(2) As illustrated in FIG. 1B, when a method is employed in which
the lower coating film 13a is formed by flexographic printing and
then flexographic printing is performed again to form the upper
coating film 13b and thereafter the upper coating film 13b and the
lower coating film 13a are hardened, cracking occurs on the
occasion of cleaning and rubbing treatment afterwards when the
thickness of the protrusion 16 in the vicinity of the edge 14
approaches approximately 2000 .ANG.. In FIG. 1B, the thickness
limit of the surface protection film that can be formed is 1000
.ANG..
(3) As illustrated in FIG. 2A, the lower coating film 13a the film
thickness of which is about 650 .ANG. is formed, and then, as
illustrated in FIG. 2B, the upper coating film 13b the film
thickness of which is about 650 .ANG. is formed. At this time, the
upper coating film 13b is formed such that an edge 18 of the upper
coating film 13b is positioned approximately 200 .mu.m inside from
the edge 14 of the lower coating film 13a. A protrusion 17 of the
lower coating film 13a does not overlap with a protrusion 19 of the
upper coating film 13b. Even at the part at which the sum of the
film thickness of the lower coating film 13a and that of the upper
coating film 13b is the maximum (namely, where the protrusion 19 is
generated), the film thickness is approximately 1950 .ANG., which
is lower than 2000 .ANG.. Accordingly, in FIGS. 2A and 2B, a
surface protection film the film thickness of which is 1300 .ANG.
can be formed and the film thickness of the part where the
protrusion 19 is generated is only approximately 1950 .ANG.. With
this, no cracking occurs.
As described above, Patent Literature 1 discloses that, in forming
an insulator film by flexographic printing, cracking occurs when a
protrusion generated on an edge of the insulator film is thick, and
that the insulator film is formed by double coating in which the
edges are shifted so that a thick insulator film can be formed and
yet occurrence of cracking can be avoided.
Such a protrusion generated when an insulator film is formed by
flexographic printing is generated not only on the outer periphery
of a printing pattern but also inside the printing pattern. For
example, when there is a hole that is a part not printed inside the
printing pattern (a blank space in which no ink is transcribed), a
protrusion is generated around the hole.
On the other hand, with respect to the insulator film, in addition
to the one used as a surface protection film as disclosed in Patent
Literature 1, there is one that is formed between two conductor
films, for example. When this insulator film formed between two
conductor films includes a through hole for connecting the two
conductor films and conducting the connected films, the printing
pattern is to have a hole corresponding to the through hole. With
this, a protrusion is generated around the through hole in the
insulator film.
When in the insulator film there is a protrusion around the through
hole that is used for connecting the two conductor films, in other
words, used for conductor joining and thus the film thickness of
the insulator film is large thereat, a conductor joining failure is
caused. This will be explained below with reference to the
drawings.
FIG. 3A illustrates a schematic structure for the explanation. In
this structure, a first conductor film 22, an insulator film 23 and
a second conductor film 24 are sequentially layered in order on a
substrate 21. In FIG. 3A, reference numeral 25 represents a through
hole provided on the insulator film 23 to connect the second
conductor film 24 to the first conductor film 22.
FIG. 3B illustrates a cross section of the part of the through hole
25. With a protrusion 23a of the insulator film 23, the film
thickness of the insulator film 23 around the through hole 25 is
large. With this, the second conductor film 24 is to be formed on a
part having a large level difference. For this reason, on the parts
surrounded by broken lines in FIG. 3B, defects of the second
conductor film 24 which raise problems of electrical conduction
continuity are generated, that is, poor electrical connection
between the two conductor films due to breaks is generated.
FIG. 3C illustrates a cross section of the part of an outer
periphery edge of the insulator film 23 formed on the first
conductor film 22. A protrusion 23b of the insulator film 23 causes
bleeding of the insulator film 23, and thus causes displacement of
the insulator film 23 from the position on which the insulator film
23 is to be formed and impairs the edge linearity of the insulator
film 23.
SUMMARY OF THE INVENTION
In view of the problem described above, an object of the present
invention is to provide a method of forming an insulator film by
flexographic printing and a flexographic printing plate, with which
generation of protrusions on an edge of a printing pattern can be
prevented.
A method according to the present invention includes a step of
forming an insulator film on a printing object by using ink as an
insulator film material and a flexographic printing plate with
halftone dots convexly formed on a convex portion thereof that
defines a printing pattern. A halftone dot condition change region
with a condition of the halftone dots varied such that an ink
retention volume therein is smaller than that in other region on
the convex portion is provided on a part of the convex portion
corresponding to an edge of the printing pattern.
The flexographic printing plate according to the present invention
is a flexographic printing plate with halftone dots convexly formed
on a convex portion thereof that defines a printing pattern. A
halftone dot condition change region with a condition of the
halftone dots varied such that an ink retention volume therein is
smaller than that in other region on the convex portion is provided
on a part of the convex portion corresponding to an edge of the
printing pattern.
EFFECTS OF THE INVENTION
The present invention can prevent generation of a protrusion in a
film thickness direction, around an edge of a printing pattern.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a sectional view illustrating a part of an edge of an
insulator film formed by conventional flexographic printing,
FIG. 1B is a sectional view illustrating a part of an edge of an
insulator film formed by double coating (overprinting) by
conventional flexographic printing,
FIG. 2A is a sectional view illustrating a part of an edge of an
insulator film formed by conventional flexographic printing,
FIG. 2B is a sectional view illustrating a state in which
overprinting of the insulator film is performed on the structure
illustrated in FIG. 2A by flexographic printing with edges
shifted,
FIG. 3A is a diagram illustrating a schematic structure in which an
insulator film having a through hole, which is formed by
flexographic printing, is present between two conductor films,
FIG. 3B is an enlarged sectional view of a part of the through hole
of the insulator film illustrated in FIG. 3A,
FIG. 3C is an enlarged sectional view of a part of an outer
periphery edge of the insulator film illustrated in FIG. 3A,
FIG. 4A is a diagram for explaining a structure of a flexographic
printing plate of an embodiment according to the present
invention,
FIG. 4B is an enlarged sectional view illustrating a part of a
through hole of an insulator film when the insulator film between
two conductor films is print-formed with the flexographic printing
plate having the structure illustrated in FIG. 4A,
FIG. 4C is an enlarged sectional view illustrating a part of an
outer periphery edge of the insulator film when the insulator film
is print-formed with the flexographic printing plate having the
structure illustrated in FIG. 4A,
FIG. 5A is a plan view illustrating outline of a touch panel to
which an embodiment of the insulator film formation method by
flexographic printing according to the present invention is
applied, and
FIG. 5B is a partial enlarged sectional view of FIG. 5A,
FIG. 6A is a vertical sectional view of halftone dots convexly
formed on a convex portion,
FIG. 6B is a vertical sectional view of halftone dots convexly
formed on a convex portion, a number of lines of the same being
larger than that shown in FIG. 6A, and
FIG. 6C is a vertical sectional view of halftone dots convexly
formed on a convex portion, a number of lines of the same being
larger than that shown in FIG. 6B.
DETAILED DESCRIPTION
An embodiment of the present invention will be described on the
basis of a working example with reference to the drawings.
FIG. 4A illustrates a structure of a flexographic printing plate of
an embodiment according to the present invention. In FIG. 4A, only
a convex portion 31 defining a printing pattern of the flexographic
printing plate is illustrated and illustration of halftone dots
convexly formed on the convex portion 31 is omitted.
The convex portion 31 of the flexographic printing plate
illustrated in FIG. 4A is designed to form an insulator film 23
illustrated in FIG. 3A described above. In this example, halftone
dot condition change regions 41 and 42 are provided on the convex
portion 31, in which conditions of halftone dots for transferring
an ink as an insulator film material, such as polyimide, epoxy
resin, or acrylic resin, from an anilox roll to a printing object
are varied relative to other region on the convex portion 31. It
should be noted that, in FIG. 4A, the halftone dot condition change
regions 41 and 42 are illustrated in a hatched manner.
The halftone dot condition change region 41 is provided as a
loop-shaped region around a hole 32 of the printing pattern
corresponding to a through hole 25 (see FIG. 3A) formed on the
insulator film 23. The halftone dot condition change region 42 is
provided over the entire outer periphery of the printing pattern.
The halftone dot condition is selected such that an ink retention
volume in each of halftone dot condition change regions 41 and 42
is smaller than that in other region (namely, the region other than
the halftone dot condition change regions 41 and 42). In this
example, the halftone dot condition in the halftone dot condition
change region 41 is further varied in a stepwise fashion and
concentrically in the loop-shaped region as described later. The
widths of the halftone dot condition change regions 41 and 42
(widths measured from the printing pattern edges) are about 0.5 to
5 mm, for example.
FIGS. 4B and 4C illustrate a cross section of the through hole 25
on the insulator film 23 and a cross section of a part of an outer
periphery edge of the insulator film 23 positioned on a first
conductor film 22, respectively, when the flexographic printing
plate with the halftone dot condition change regions 41 and 42
provided thereon as described above is used to form the insulator
film 23. The insulator film 23 is formed by flexographic printing
on the first conductor film 22 formed on a substrate 21, and a
second conductor film 24 is further formed on the insulator film
23, similarly to the structure in FIG. 3A described above.
By providing the halftone dot condition change regions 41 and 42 on
parts corresponding to the printing pattern edges, in which the ink
retention volumes are smaller, generation of protrusions at the
printing pattern edges of the insulator film 23 can be prevented.
Furthermore, by selecting halftone dot conditions for each region,
or preferably by adopting the halftone dot conditions each varying
in a stepwise fashion, an edge shape of the insulator film 23 as
illustrated in FIG. 4B or an edge shape of the insulator film 23 as
illustrated in FIG. 4C can be obtained.
In FIG. 4B, protrusions are not generated on the insulator film 23,
and the insulator film 23 is formed such that the inner wall
surface of the through hole 25 forms a gentle slope surface towards
the first conductor film 22. With this, the second conductor film
24 can be desirably formed with no defects of the second conductor
film 24 generated as illustrated in FIG. 3B, whereby poor
electrical connection of the second conductor film 24 to the first
conductor film 22 can be prevented.
On the other hand, because the part of the outer periphery edge of
the insulator film 23 is formed so as to have no protrusions as
illustrated in FIG. 4C, bleeding on the insulator film 23 can be
suppressed.
The halftone dot condition will now be described. The halftone dot
condition includes the number of lines (unit: LPI (lines per inch))
and the halftone dot area ratio (namely, halftone dot percent). By
changing these values, the ink retention volume (in other words,
the amount of ink transcribed to the printing object) can be
adjusted.
An example of specific values for the halftone dot condition will
be described.
When the halftone dot condition of the flexographic printing plate
forming the insulator film 23 is set to 300 LPI and the halftone
dot area ratio of 70%, the halftone dot condition of the halftone
dot condition change region 41 is defined such that parts 41a, 41b,
41c and 41d in FIG. 4A which form the loop-shaped region thereof
are changed in a stepwise fashion and concentrically from the
outside to the inside, from 400 LPI to 500 LPI and then to 600 LPI
with the halftone dot area ratio of 70% unchanged, for example.
This can reduce the ink retention volume in the halftone dot
condition change region 41 and form the gentle slope surface on an
edge of the insulator film 23.
As exemplified above, the halftone dots in the present disclosure
have characteristic that can reduce an ink retention volume by
increasing only the value of the number of lines while constantly
maintaining the value of the halftone dot area ratio.
Examples of manners that increase only the value of the number of
lines while constantly maintaining the value of the halftone dot
area ratio are as shown in FIGS. 6A to 6C. FIGS. 6A to 6C
illustrate vertical sectional views of halftone dots convexly
formed on the convex portion 31.
Here, the halftone dot area ratio, which is the ratio of the area
occupied by the halftone dots over the whole of the convex portion
31, in a plain viewed onto the convex portion 31 from above, is
constant among FIGS. 6A to 6C, but the number of lines, which is
the number of halftone dots per unit length in the transverse
direction of the figures, increase in order of FIGS. 6A, 6B, and
6C. Moreover, the ink retention volume of the halftone dots
conversely decreases in order of FIGS. 6A, 6B, and 6C, and is at a
minimum in FIG. 6C.
Protrusions on a printing pattern edge depend on the printing
direction when the insulator film 23 is formed by flexographic
printing. Especially, prominent protrusions are generated on an
edge at the rear end side in the printing direction. The halftone
dot condition change region 42 in FIG. 4A is provided over the
entire outer periphery of the printing pattern. However, the
halftone dot condition change region 42 may be provided only on a
part corresponding to the edge at the rear end side in the printing
direction of the printing pattern, for example. In this case, the
halftone dot condition change region 42 is to be provided only a
part of a region in contact with the outer periphery of the convex
portion 31. When the arrow indicated by a reference character "a"
in FIG. 4A represents the printing direction, the halftone dot
condition change region 42 is to be provided only on the side of a
right side 31a of the convex portion 31.
Furthermore, the halftone dot condition in each of the halftone dot
condition change regions 41 and 42 may be set in view of the
printing direction. For example, when the printing direction is
defined by the arrow with the reference character "a" and
sufficient connection of the second conductor film 24 with the
first conductor film 22 can be achieved by absence of protrusions
even without a slope surface formed on the inner wall surface of
the through hole 25, the halftone dot area ratio of each of the
sides 41a, 41b, 41c, and 41d on the halftone dot condition change
region 41 formed in a square frame shape may be set to 70% and the
number of line may be set to 600 LPI for the side 41a, 500 LPI for
the side 41b, and 400 LPI for the sides 41c and 41d.
Furthermore, the halftone dot condition in each of the halftone dot
condition change regions 41 and 42 may be defined by a combination
of a stepwise variation towards the printing pattern edge inside
the regions and a variation based on the printing direction.
The insulator film formation method by flexographic printing and
the flexographic printing plate as an embodiment of the present
invention have been described above. According to the embodiment of
the present invention, a phenomenon of bleeding of the printing
pattern edge caused by the protrusions can be prevented. According
to the embodiment of the present invention, when the insulator film
formed between two conductor films has a through hole for
connecting the two conductor films, for example, a phenomenon of
poor electrical connection caused by protrusions around the through
hole on the insulator film can be prevented.
Next, as a specific example in which the present invention can be
applied, a capacitive touch panel will be described.
FIGS. 5A and 5B illustrate a capacitive touch panel in which an
embodiment according to the present invention is applied. The touch
panel includes a rectangular transparent substrate 50. On the
transparent substrate 50, first sensor electrode arrays 61 and
second sensor electrode arrays 62 are formed. The first sensor
electrode arrays 61 extend along the X direction that is parallel
with the short sides of the transparent substrate 50 and are
arranged in parallel with the Y direction that is parallel with the
long sides of the transparent substrate 50. The second sensor
electrode arrays 62 extend along the Y direction and are arranged
in parallel with the X direction.
From one end of each of the first sensor electrode arrays 61, a
lead-out wire 71 is led out. From one end of each of the second
sensor electrode arrays 62, a lead-out wire 72 is led out. These
lead-out wires 71 and 72 extend to terminal parts 73 formed in the
vicinity of the center of one of the short sides of the transparent
substrate 50.
Each of the first sensor electrode array 61 includes island-shaped
electrode parts 61a arranged in the X direction and connection
parts 61b, each of the connection parts 61b connecting adjacent two
of the island-shaped electrode parts 61a. Each of the second sensor
electrode array 62 includes island-shaped electrode parts 62a
arranged in the Y direction and connection parts 62b, each of the
connection parts 62b connecting adjacent two of the island-shaped
electrode parts 62a.
The touch panel has a structure in which a first conductor film 81,
an insulator film 82, a second conductor film 83, and a protection
film 84 are sequentially laminated on the transparent substrate 50,
as illustrated in FIG. 5B. The first sensor electrode arrays 61,
the lead-out wires 71 and 72, and the terminal parts 73 are formed
by the first conductor film 81, and the second sensor electrode
arrays 62 are formed by the second conductor film 83 that is
insulated from the first conductor film 81 with the insulator film
82. The first sensor electrode arrays 61 and the second sensor
electrode arrays 62 are crossed in such a way as to be insulated
from each other. The connection parts 61b and 62b are positioned
such that the connection parts 61b and 62b are overlapped with each
other. It should be noted that, in FIG. 5A, illustration of visible
outlines of the insulator film 82 and the protection film 84 is
omitted.
Each of the second sensor electrode arrays 62 is connected to the
lead-out wire 72 at the part of a through hole 91 formed on the
insulator film 82. The through holes 91 are provided so as to
correspond to the positions where the island-shaped electrode parts
62a at the lower end in the Y direction of the second sensor
electrode arrays 62 are positioned, as illustrated in FIG. 5A.
FIG. 5B illustrates a cross section of the part of the through hole
91. The insulator film 82 is formed by the insulator film formation
method by flexographic printing, which is an embodiment of the
present invention, and thus does not have the protrusions.
Furthermore, the inner wall surface of the through hole 91 is
formed so as to have a gentle slope surface. With this structure,
problems of electrical conduction continuity and poor electrical
connection can be prevented and the second sensor electrode arrays
62 and the lead-out wires 72 can be desirably connected, whereby
improvement in productivity can be accomplished.
It should be noted that though the detailed illustration is omitted
in FIG. 5A, the touch panel can be manufactured by a printing
process with the method including: forming each of the first sensor
electrode arrays 61, the second sensor electrode arrays 62, the
lead-out wires 71 and 72, and the terminal parts 73 as a mesh
pattern of conductor thin lines by gravure offset printing using a
conductive ink such as silver; forming the insulator film 82 by
flexographic printing as described above; and forming the
protection film 84 by flexographic printing. This can promote a
significant cost reduction.
The foregoing description of the embodiment of the invention has
been presented for the purpose of illustration and description. It
is not intended to be exhaustive or to limit the invention to the
precise form disclosed. Modifications or variations are possible in
light of the above teachings. The embodiment was chosen and
described to provide the illustration of the principles of the
invention and its practical application, and to enable one of
ordinary skill in the art to utilize the invention in various
embodiments and with various modifications as are suited to the
particular use contemplated. All such modifications and variations
are within the scope of the invention as determined by the appended
claims when interpreted in accordance with the breadth to which
they are fairly, legally, and equitably entitled.
* * * * *